1. Field of the Invention
With reference to the classification of art as established in the United States Patent and Trademark Office the present invention is found in the general Class entitled, "Furnaces" (Class 110) and in the subclass entitled, "from exhaust" (subclass 162).
Also of interest is art found in the general Class entitled, "Heating Systems" (Class 237) and the subclass entitled, "air-flue heated" (subclass 55).